Spring-controlled gear



Dec. 25, 1928. 1,696,797

G. FORNACA SPRING CONTROLLED GEAR Filed Nov. 26, 1927 Ira/Vania): 6001 1ZrM-dCi Patented Dec. 25, '1928.

UNITED STATES PATENT OFFICE.

GUIDO FORNTAGA, OF TURIN, ITALY.

SPRING-CONTROLLED GEAR.

Application filed November 26, 1927, Serial No. 235,953, and in ItalyAugust 25, 1927.

The present invention relates to spring means for controlling movableparts, and more particularly for controlling. valves, especially ininternal combustion engines.

The invention has for its object the provision of springmeans forexerting a resilient pressure on a member, particularly on a valve forcombustion engines and'thc like, in which the valve-controllingcoilspring (31' springs is or are divided into two or more sectionswhich operate inseries, said sections being arranged concentric with andon the extension of each other and each set of spring sections beinglocated between an abutment and a part solid with the movable member orvalve. p

In accordance with the present invention, since the period of vibrationof a coil spring increases as the number of turns and the weight of thespring are reduced, it is possible to impart to each spring section aperiod of vibration which is not in resonance with the number ofimpulses the spring controlled member or valve receives from its cam orother actuating member. I

By the present invention the essential cause of breakage of springs isremoved, said cause, as known, being the increase'in stresses acting onthe metal of the spring in consequence of the resonance of inherent.vibration of the spring with the number of impulses imparted either tothe spring or to the parts connected therewith, or to both by theactuating member or cam., I I

The annexed drawing illustrates by way of example an embodiment of thisinvention and Figure 1 is a section of a valve equipped with springs inaccordance with the invention, said section being taken on line 11 ofFigure 2;

Figure 2 is a section on line 22 of Fig. 1.

In the drawing, a valve 1 is shown which controls a duct 2 which isassumed to con-' nect, say, a carbureter or an exhaust with a cylinder(not shown) into which said duct 2 opens.

Said valve 1 has a stem 3 guided in a sleeve 4 fastened induct 2 and thefree end' of said stem 3 has a groove 5 in which are engaged ring.sections 6 having tapering outer surfaces. A disk 7 having a taperingbore is located on said ring sections 6 and the parts are assembled bymeans of a cap 8 located on theend of stem 3 and engaged claimed withdisk"? by means of a resilient split ring 9 which engages the edge ofsaid cap 8 and a concentric groove in the bore of said disk 7.

. A member,-not shown, suchas a cam or a cam controlled part, acts onthe end cap 8 of the valve stem to move said valve away from its seatand to carry it into the position shown in Fig. 1 against the action ofreturn springs 12 as hereinafter described.

protecting cup 10 is located around the gu de sleeve 4 in duct 2 and aflanged sleeve 11 engages the shoulder. 4. of sleeve 4 and has abottomradial flange 11 on which the adjacent ends of springs 12 are seated.

Coil springs .12 are located in a row varound the valve stem 3 and guidesleeve 4 and said springs are arranged between flange 11 and disk 7 andact to move the valve 1 into its closed position from its open positionshown in the drawing. Spring guiding stems 13 are fastened alternatelvon disk 7 and flange 11 said stems 13 extending each through thecentral'hollow space of'a coil spring 12 to provide a guide there Theabove construction is described and illustrated as an'example of aconstruction adaptedfor the embodiment of the present invention, saidconstruction being not per se in the present application as it isdescribed and claimed in my U. S.

Patent No. 1,605,399 dated Nov. 2,1926, but of course the features ofthe present invention as hereinafter described are not re-. stricted tothe described construction, they being capable of extensive use inconnection w1th spring gears.

In accordance with the present invention each spring comprises a numberof sections 12-12 which are concentric and aligned with each other, awasher or ring 14 being inserted between the sections 12-12 of eachspring.

In the drawin the springs are shown as consisting each 0 two sectionsbut of course they-may comprise each a larger number of sections atwill, a ring or washer 14 being inserted. between adjacent sections.

- Each set of concentric and aligned spring sections acts on the valvedisk 7 as a single spring, but in said sets each spring section has sucha number of turns and conse quentlysuch a rigidity and weight as toimpart to it an inherent vibration period which is out of resonance withrespect to the period of actuating impulses exerted on the valve andassociated springsby the member operating said valve, which member, asprevlously stated, is not shown.

By dividing the s rings into a more or less great number sectionsaccording to the speed of the engine, it is possible to avoid criticalperiods within the limits of use of the engine.

What I claim as my invention and desire to'se cure by United StatesLetters Patent 1s:

1. In a spring operated gear, a return spring comprising a number ofsections, said sections being included serially between a stationarypart and a movable part of said ear. g 2. In a valve gear, a valvereturn spring comprising a number of sections, said sections beingincluded serially between a stationary part and a movable part of saidgear.

3. In a valve gear, a valve return s ring comprising a number ofsections whic are included serially between a stationary part and amovable part of said gear, and a rigid separating member interposedbetween the a jacent ends of said sections.

4. In a valve gear, a valve return spring comprising two sectionsincluded serially between a. stationary part and a movable part of saidgear.

5. In a valve gear, a number of valve return springs each comprising anumber of sections included serially between a stationary part and amovable part of said gear.

'0 uded seria 6. In a valve gear, a number of valve return springsarrang in a circular row around the stem of the valve, each of said 5rings comprising a number-of sections inly between; a stationary partand a movable part of said ear.

7. In a valve gear, a num er of valve return springs arranged in acircular row around the stem of the valve,'each of said springscomprising a number of sections included serially between a stationarypart and a movable part of said gear, and a rigid sedparating memberinterposed between the a jacent ends of the sections of each spring.

8. In a valve gear, a number of valve return springs arranged around thestem of the valve, each of said s rings comprising a number of sectionsinc uded serially between a stationary part and a movable part of said'gear, guide members each solid with one of saidparts and extendingthrough one of said springs, and rigid rmgs each inserted between theadjacent ends of the sections of each spring and free on one of saidguide members.

9. In a valve gear. comprising an operating member whcih produces aperiodical impulse on said gear, a valve return rin comprising a numberof sections inc ude serially between a stationary part and a movablepart of said gear, each of said spring sections having an inherentvibratory period different with respect to the period of said operatingimpulses.

In testimony whereof I aflix myasignature.

GUIDO F0 NACA.

